Present invention relates to a character recognition method and apparatus for recognizing an inputted handwritten character by registering a user's unique handwriting and associated character code in a dictionary and utilizing the user's dictionary in addition to a built-in basic dictionary for character recognition.
In a conventional character recognition apparatus which is capable of registering a user's handwriting character into a recognition dictionary (user's dictionary), an inputted character pattern is recognized by utilizing a built-in basic dictionary and the user's dictionary.
In such recognition processing method, an n number of candidates of recognized character for an inputted unknown pattern are first obtained by utilizing a recognition dictionary called a basic dictionary, which is built in a recognition apparatus. Next, a user's dictionary created by the user is utilized for recognizing the unknown pattern and candidates of recognized characters are obtained.
As a result of the above process, a set of final recognized character candidates is generated by utilizing the n number (n.gtoreq.0) of character codes obtained by matching with the basic dictionary, a recognition score thereof obtained by a recognition operation (generally obtained by operating a difference between an unknown pattern and a learned pattern), the k number (k.gtoreq.0) of character codes obtained by matching with the user's dictionary, and a recognition score thereof obtained by the recognition operation. To obtain the set of final recognized character candidates, both recognition scores obtained by matching with each of the recognition dictionaries are compared and merged.
For registering a user's unique handwriting in the user's dictionary, the recognition apparatus comprises handwritten character registering means for storing the user's handwritten character and the associated character code in pairs.
However, in a character recognition apparatus such as that of the above conventional example which outputs a recognition result by utilizing the basic dictionary and the user's dictionary, a character is not always recognized as intended by a user although a user inputs a character that has been registered in the user's dictionary. This is due to the fact that it is almost impossible for a user to write a character having identical characteristics to the character registered in the dictionary. Moreover, if a registered character resembles another character in the basic dictionary or in the user's dictionary, an inputted character is not always matched correctly with the corresponding character in the user's dictionary; instead, the resembling character is outputted as a first candidate of the recognized character.
Meanwhile, if one of the registered characters is written frequently, the user's handwriting of the character is consistent. Therefore, the character is highly likely to be recognized correctly since it is written the same way as the registered character. However, for a character which is not written frequently, it is likely that the character is inputted differently than the registered handwritten character, therefore, a recognition result may vary depending on the type of registered character.
Accordingly, a satisfactory recognition result is difficult to obtain because of the foregoing problem.